1. Field of the Invention
The present invention relates to a transversal filter, and more particularly to a transversal filter having an analog shift register comprising a series input and a plurality of parallel outputs, in which an input signal can be supplied to the series input of the form of successively-sampled signal values and signals may be tapped at the parallel outputs and supplied to a summer and/or subtractor whose output signal represents the filtered signal, and in which a plurality of signal weighting devices are assigned to the stages of the shift register.
2. Description of the Prior Art
A transversal filter of the general type set forth above is known, for example, from the publication Siemens Forschungs- und Entwicklungsberichten, Vol. 7, No. 3, 1978, Springer-Verlag 1978, pp. 138-142, with particular reference to FIG. 1a. Weighting factors a.sub.0 -a.sub.n are assigned to the signal weighting devices of the individual register stages which are connected in series with the parallel outputs, the weighting factors corresponding to the filter coefficients referenced a.sub.0 -a.sub.n in the equation EQU H(z)=a.sub.0 =a.sub.1 z+a.sub.2 .multidot.z.sup.2 + . . . +a.sub.n .multidot.z.sup.n ( 1)
where H(z) represents the system function of the filtered signal and z represents the delay time which a sampled signal value experiences when traversing one stage of the shift register. It is disadvantageous, however, that the weighting factors a.sub.0 -a.sub.n can assume greatly divergent values for realizing specific filter curves, thus complicating realization of the filter circuit.